The present invention relates to a loudspeaker system for the passenger compartment of a vehicle, such as an automobile, in which at least two speakers are arranged in the passenger compartment to provide sources of sound on opposite sides thereof.
It is known to provide motor vehicles with loudspeaker systems in which separate speakers are arranged on opposite sides of the vehicle passenger compartment. One system of this type is disclosed, for example, in the West German patent publication (Offenlegungsschift) No. 2,402,028. As is well known, multiple speakers arranged at various corners of a passenger compartment serve either to create the impression of stereophonic sound or to improve the quality of tone for the passengers sitting close to the individual speaker locations.
The quality of sound reproduction in motor vehicles is determined primarily by the nature and quality of the individual speakers. However, even when high quality speakers are used, it is difficult to reproduce the lower audio frequencies because of the limited, closed space conditions within the passenger compartment. In order to remedy this problem, it is known, for example from the German Utility Model patent No. 7,442,448 to de-emphasize the reproduction of the medium and high audio frequencies.
Low frequency audio reproduction may also be improved by providing an acoustic baffle of the required dimensions. If the speakers are arranged in "boxes" or enclosures filled with sound attenuating material, they will radiate sound with a lower cutoff frequency, as is required for realistic tonal characteristics. However, speaker systems constructed in accordance with this known principle have had such a large total volume that they have not been considered practical for use in motor vehicles.
It is an object of the present invention to improve the quality of sound reproduction in the passenger compartment of a vehicle, such as an automobile.